This application claims the priority of German application 198 03 146.4, filed in Germany on Jan. 28, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an energy-absorbing deformation system for a motor vehicle with at least one collapsing section that is movable with energy absorption from an extended absorption position into a collapsed deformation position.
Energy-absorbing deformation systems of this kind in the form of collapsing tubes in which energy absorption takes place as the result of rolling bending of the collapsing tube walls are generally known. Special reference is made here to German Patent Document DE-AS 1,931,844, which shows an impact-damping device for a motor vehicle, in which a ring made of plastically deformable metal is additionally provided as the guide part for the collapsing tube, said ring being rounded to face the collapsing tube. A similar energy-absorbing deformation system for a motor vehicle is known from German Patent Document DE 42 06 716 A1.
A goal of the invention is to provide an energy-absorbing deformation system of the type referred to above that can be accommodated in a compact manner by comparison with the prior art.
This goal is achieved according to the invention by virtue of the fact that the at least one collapsing section is held in its deformation position in its normal resting position and in that a drive device is associated with the at least one collapsing section, by means of which device the collapsing section can be moved abruptly into an absorption position when the drive device is activated. During the normal operation of the motor vehicle, the collapsing section is therefore in its telescoped deformation position, so that it has a reduced size and can be positioned in a visually unobtrusive manner in the vehicle. The fact that the collapsing section is pressed by the drive device abruptly into its absorption position means that it can when necessary nevertheless be varied accordingly in proper time for energy absorption. The solution according to the invention is provided for absorbing impact, with an important advantage of the solution according to the invention being the suitability of the deformation system for multiple acceptance of corresponding impact loads. The drive device is able to bring the collapsing section, depending on the fatigue phenomena of the material, back to the absorption position for a plurality of successive exposures to impact. The deformation system according to the invention is preferably located in the vicinity of the external contours of the vehicle, especially in the front or rear area or at the sides of the vehicle.
In certain embodiments of the invention, the drive device is connected to an activation control integral with the vehicle that controls the drive device as a function of signals from an impact sensor system. As a result, the displacement of the collapsing section from the telescoped deformation position into an extended absorption position takes place similarly to the expansion of airbag systems in the vehicle interior. Advantageously, a traffic monitoring camera is associated with the activation control, said camera triggering the activation control and hence actuating the drive device shortly before a vehicle impact occurs, so that the collapsing section already presents its increased deformation length when the vehicle impact occurs.
In certain preferred embodiments of the invention, the drive device is designed as a linearly operating pressure device which acts on the at least one collapsing tube upon activation, opposite to the direction of action of a deformation force. As a result, the collapsing section is guided opposite to the directional action of an impact shortly before this impact load is applied in order to make the increased deformation length available for energy absorption.
In certain preferred embodiments of the invention, she pressure device can be controlled by means of the activation control at various energy levels in such fashion that the at least one collapsing section can be moved into various absorption positions. As a result it is possible, depending on the subsequent impact load, to provide a variety of energy absorption capacities, with the activation control, for this purpose, evaluating in particular the respective road speed and/or the relative speed with respect to the obstacle that appears.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.